Doreen Cronin and Betsy Lewin's Caldecott Honor-winning book is celebrating its twenty-year anniversary with a brand-new edition featuring bonus content! Click, clack, MOO. Click, clack, MOO. Clickety, clack, MOO. It was the typewriter heard 'round the world. When Farmer Brown's cows began leaving him notes, that's when his troubles started--and the animals' fun commenced! Celebrate twenty years of barnyard shenanigans with this special anniversary edition of the story that started it all, Click, Clack, Moo--now with a bonus poster in the inside cover!